Contemporary footwear is typically designed for much more specific uses than footwear of the past. This is evidenced by the fact that a person may own numerous articles of footwear, for varying activities and situations. Among other types of footwear, a person may have several pairs of dress shoes, several pairs of sneakers or other athletic footwear for different exercising activities such as cross-training, and footwear adapted for cold or inclement weather wear. In addition to these standard articles of footwear, there exists footwear adapted for very specific activities. For example, hiking or trail running may require different types of boots/sneakers depending upon the type of terrain being traversed.
Despite the sheer amount of differing footwear, situations often arise where footwear adapted for a specific activity is required to be utilized in connection with a different activity. For example, varying terrain encountered during a hike or trail run may require footwear with differing sole stiffness. The level of stiffness/flexibility of the sole necessarily determines the amount of flexibility allowed in the footwear. While a hiker walking on flat ground may desire an article of footwear with a more flexible sole, a stiffer sole may be desirable while hiking rocky or steep terrain. Given the fact that most hiking trails vary from flat to steep and bumpy terrain, a single boot/sneaker may not be capable of providing the most desirable comfort to its wearer. In addition, other such situations exist in which a different sole stiffness may be desired or required. For instance, boots/shoes designed for wear at a construction or other similar jobsite may be manufactured with a stiff sole to be suitable for wearing while working. However, the same boots/shoes may not be properly adapted for driving or walking to the jobsite or non-work related activities.
Heretofore, multiple pairs of footwear have been required for adaptation to particular activities. Depending upon the activity, this may necessarily require a wearer to carry different types of footwear at a given time. For example, as mentioned above, a hiker may ideally wish to carry and change footwear depending upon the terrain encountered, and a worker may ideally wear one article of footwear on his/her commute to work, and another while on the jobsite. Thus, it would be desirable and advantageous to provide a single article of footwear that allows for differing sole stiffness.
Therefore, there exists a need for articles of footwear having adjustable sole stiffness.